Collaborative Research: Constraining the tempo and dynamics of Cambrian Earth systems in western Laurentia

合作研究：限制劳伦西亚西部寒武纪地球系统的节奏和动态

基本信息

批准号：
1955078
负责人：
Karl Karlstrom
金额：
$ 26.3万
依托单位：
University of New Mexico
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2020
资助国家：
美国
起止时间：
2020-08-01 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1955078&HistoricalAwards=false
关键词：
Collaborative Research Constraining tempo dynamics

项目摘要

Rocks from the Cambrian Period (539-485 million years ago) contain fossils that reveal the first diversification of animals on Earth. The timing, causes, and impacts of this “Cambrian Explosion” are poorly understood. Yet clues to understanding this event are buried in Cambrian strata that formed as oceans flooded the world’s continents, and coastal environments blanketed the landscape with vast swaths of sand, mud, and fossils. One of the best-preserved records of these events is in the bottom of the Grand Canyon—in a package of sedimentary rocks known as the Tonto Group. Although the Tonto Group has been studied for nearly 150 years, the availability of new techniques makes it time to revisit these classic exposures. This project will decipher how, when, and why these rocks were deposited, and lead to greater understanding of the Cambrian Explosion of life on Earth. The broader impacts of this research include mentoring a suite of post-doctoral, graduate, and undergraduate scholars, including recruiting and training Hispanic and Native American students. Impacts also include outreach and distance learning through the Denver Museum of Nature and Science, to help this research inspire younger audiences, including 4th-12th graders in rural, first-generation, first-nation, inner-city, and culturally diverse settings. Finally, this project will reach many of the six million annual visitors to Grand Canyon National Park through Park programs, exhibits, media, and NSF-sponsored field forums on Grand Canyon geology. Cambrian rocks record dramatic changes in Earth systems including atmospheric oxygenation events, large magnitude perturbations to the carbon cycle, and the punctuated evolution of animal life. These events played out within the global transgressive inundation of continents by advancing oceans that deposited sheet sands, muds, and carbonates. Underpinning the research plan is a novel, integrative approach to calibrating the timing and tempo of this marine transgression. This approach combines: a) radioisotopic dating of the youngest, penecontemporaneously deposited zircon crystals, which are hidden amidst the detritus making up these sedimentary rocks; b) identifying changes in the types of fossils in the same rocks, and; c) documenting changes in mineral, chemical, and physical signatures of these rocks that record simultaneous, related changes in the Cambrian Earth system—such as changes in sea level or the collision and breakup of continents. Initial work has shown that the Tonto Group of the Grand Canyon is tens of millions of years younger than previously thought, that seas flooded North America relatively quickly, and that other continental margins experienced the same event. The project will expand upon a pilot study that was conducted in the Grand Canyon, and augment it with contemporaneous strata throughout the western U.S. to test hypotheses about how these flooding episodes relate to global biologic, tectonic, and geophysical events and processes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

寒武纪时期（距今 539-4.85 亿年前）的岩石中含有的化石揭示了地球上动物的首次多样化。人们对这场“寒武纪大爆发”的时间、原因和影响知之甚少，但了解这一事件的线索却被埋没了。在海洋淹没世界大陆时形成的寒武纪地层中，沿海环境覆盖着大片的沙子、泥土和化石，这是保存最完好的记录之一。这些事件发生在大峡谷底部，位于被称为通托群 (Tonto Group) 的沉积岩中，虽然人们对通托群 (Tonto Group) 的研究已有近 150 年的历史，但新技术的出现让我们有时间重新审视这些经典的发现。该项目将破译这些岩石是如何、何时以及为何沉积的，并有助于更好地了解地球上生命的寒武纪大爆发。这项研究的更广泛影响包括指导一系列博士后、研究生和本科生学者，其中包括。招聘影响还包括通过丹佛自然科学博物馆进行外展和远程学习，以帮助这项研究激励年轻受众，包括农村、第一代、原住民、国内的 4 至 12 年级学生。最后，该项目将通过公园项目、展览、媒体和 NSF 赞助的大峡谷地质实地论坛，向每年 600 万游客展示大峡谷地质的巨大变化。地球系统，包括大气氧合事件、碳循环的大规模扰动以及动物生命的间断进化，这些事件是在全球大陆的海侵淹没过程中发生的，通过推进海洋沉积了席状沙、泥浆和碳酸盐，这是一项新颖的研究计划的基础。，校准这种海洋侵入的时间和节奏的综合方法该方法结合了：a）对最年轻的准同期沉积的锆石进行放射性同位素测年。晶体，隐藏在构成这些沉积岩的碎屑中；b) 识别同一岩石中化石类型的变化；c) 记录这些岩石的矿物、化学和物理特征的变化，记录同时相关的信息。寒武纪地球系统的变化，例如海平面的变化或大陆的碰撞和分裂，初步研究表明，大峡谷的通托群比之前认为的要年轻数千万年，海洋淹没了北美。很快，其他大陆边缘也经历了同样的事件，该项目将扩展在大峡谷进行的试点研究，并将其扩展到美国西部的同期地层，以测试有关这些洪水事件与全球生物有何关系的假设。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Novel age constraints for the onset of the Steptoean Positive Isotopic Carbon Excursion (SPICE) and the late Cambrian time scale using high-precision U-Pb detrital zircon ages

使用高精度 U-Pb 碎屑锆石年龄对 Steptoean 正同位素碳偏移 (SPICE) 和晚寒武世时间尺度的起始年龄进行限制

DOI：
10.1130/g50434.1
发表时间：
2022-10
期刊：
Geology
影响因子：
5.8
作者：
Cothren, Hannah R.;Farrell, Thomas P.;Sundberg, Frederick A.;Dehler, Carol M.;Schmitz, Mark D.
通讯作者：
Schmitz, Mark D.

Redefining the Tonto Group of Grand Canyon and recalibrating the Cambrian time scale

重新定义大峡谷通托群并重新校准寒武纪时间尺度

DOI：
10.1130/g46755.1
发表时间：
2020-02
期刊：
Geology
影响因子：
5.8
作者：
Karlstrom, K.E.;Mohr, M.T.;Schmitz, M.D.;Sundberg, F.A.;Rowland, S.M.;Blakey, R.;Foster, J.R.;Crossey, L.J.;Dehler, C.M.;Hagadorn, J.W.
通讯作者：
Hagadorn, J.W.

The Grand Canyon National Park (USA) water corridor: water supply, water quality, and recharge along the Bright Angel Fault

大峡谷国家公园（美国）水走廊：沿光明天使断层的供水、水质和补给

DOI：
10.1007/s10040-023-02633-6
发表时间：
2023-04
期刊：
Hydrogeology Journal
影响因子：
2.8
作者：
Curry, Brionna H.;Crossey, Laura J.;Karlstrom, Karl E.
通讯作者：
Karlstrom, Karl E.

Tectonic controls on basement exhumation in the southern Rocky Mountains (United States): The power of combined zircon (U-Th)/He and K-feldspar 40Ar/39Ar thermochronology

落基山脉南部基底折返的构造控制（美国）：组合锆石 (U-Th)/He 和钾长石 40Ar/39Ar 热年代学的力量

DOI：
10.1130/g49141.1
发表时间：
2021-06
期刊：
Geology
影响因子：
5.8
作者：
Ricketts, Jason W.;Roiz, Jacoup;Karlstrom, Karl E.;Heizler, Matthew T.;Guenthner, William R.;Timmons, J. Michael
通讯作者：
Timmons, J. Michael

Zircon (U-Th)/He thermochronology reveals pre-Great Unconformity paleotopography in the Grand Canyon region, USA: COMMENT

锆石 (U-Th)/He 热年代学揭示了美国大峡谷地区大不整合前的古地形：评论

DOI：
10.1130/g49843c.1
发表时间：
2022-03
期刊：
Geology
影响因子：
5.8
作者：
Karlstrom, Karl E.;Guenthner, William R.;Thurston, Olivia G.;Heizler, Matthew T.;Ricketts, Jason W.;Timmons, J. Michael
通讯作者：
Timmons, J. Michael